Method for producing light-emitting device

Abstract

To remove a deteriorated layer generated in forming a scribing trench by laser irradiation. A scribing trench is formed by irradiating a laser beam along a device dividing line on the rear surface of a substrate. At this time, a deteriorated layer is formed on the bottom surface or side surface of the scribing trench. Next, a protective film is formed so as to cover the entire top surface of the device structure, and the deteriorated layer is removed by wet etching. Wet etching is performed by alternately repeating BHF (buffered hydrofluoric acid) wet etching and MEA (monoethanolamine) wet etching several times.

What is claimed is: 
     
       1. A method for producing a light-emitting device, the method comprising;
 forming a scribing trench by irradiating a laser beam along a device dividing line on the rear surface of a Group III nitride semiconductor substrate having a plurality of light-emitting device structures on the surface thereof; 
 removing a deteriorated layer formed in the scribing trench by alternately and repeatedly performing wet etching using a hydrofluoric acid based solution and wet etching using an alkaline solution; and 
 dividing the substrate into light-emitting devices by dividing the substrate along the scribing trench. 
 
     
     
       2. The method for producing a light-emitting device according to  claim 1 , wherein the number of repetitions of wet etching using a hydrofluoric acid based solution and wet etching using an alkaline solution in removing the deteriorated layer is preferably three times or more. 
     
     
       3. The method for producing a light-emitting device according to  claim 2 , wherein the hydrofluoric acid based solution is buffered hydrofluoric acid. 
     
     
       4. The method for producing a light-emitting device according to  claim 2 , wherein the temperature of the hydrofluoric acid based solution is 50° C. or more. 
     
     
       5. The method for producing a light-emitting device according to  claim 2 , wherein the alkaline solution contains methanol amine. 
     
     
       6. The method for producing a light-emitting device according to  claim 2 , wherein the temperature of the alkaline solution is 100° C. or more. 
     
     
       7. The method for producing a light-emitting device according to  claim 1 , wherein the hydrofluoric acid based solution is buffered hydrofluoric acid. 
     
     
       8. The method for producing a light-emitting device according to  claim 7 , wherein the temperature of the hydrofluoric acid based solution is 50° C. or more. 
     
     
       9. The method for producing a light-emitting device according to  claim 7 , wherein the alkaline solution contains methanol amine. 
     
     
       10. The method for producing a light-emitting device according to  claim 9 , wherein forming a protective film for covering an entire top surface of the light-emitting device structure before removing the deteriorated layer. 
     
     
       11. The method for producing a light-emitting device according to  claim 9 , wherein a thermal release tape is attached to the top surface of the light-emitting device structure to support the wafer before laser irradiation, a scribing trench is formed by laser irradiation, and then the thermal release tape is peeled off from the light-emitting device structure by heating. 
     
     
       12. The method for producing a light-emitting device according to  claim 11 , wherein forming a protective film for covering an entire top surface of the light-emitting device structure after peeling off the thermal release and before removing the deteriorated layer. 
     
     
       13. The method for producing a light-emitting device according to  claim 7 , wherein the temperature of the alkaline solution is 100° C. or more. 
     
     
       14. The method for producing a light-emitting device according to  claim 1 , wherein the temperature of the hydrofluoric acid based solution is 50° C. or more. 
     
     
       15. The method for producing a light-emitting device according to  claim 14 , wherein the alkaline solution contains methanol amine. 
     
     
       16. The method for producing a light-emitting device according to  claim 14 , wherein the temperature of the alkaline solution is 100° C. or more. 
     
     
       17. The method for producing a light-emitting device according to  claim 1 , wherein the alkaline solution contains methanol amine. 
     
     
       18. The method for producing a light-emitting device according to  claim 1 , wherein the temperature of the alkaline solution is 100° C. or more. 
     
     
       19. The method for producing a light-emitting device according to  claim 1 , wherein a thermal release tape is attached to the top surface of the light-emitting device structure to support the wafer before laser irradiation, a scribing trench is formed by laser irradiation, and then the thermal release tape is peeled off from the light-emitting device structure by heating. 
     
     
       20. The method for producing a light-emitting device according to  claim 19 , wherein the thermal release tape has a thermal release temperature of 100° C. or more, and an adhesive strength of 5 N/20 mm or more.